Ditches formed in the earth for conveying water to a point or area of use have been common for generations throughout the world. Ditches have been used to transport both potable and irrigation water. Earthen irrigation ditches continue to be significant transporters of water, particularly to convey surface irrigation water to crops. As used in this document, the term “ditch” includes any excavation dug in the earth that may be referred to as a drain, channel, canal or acequia. Earthen ditches, relying on principles of gravity flow to transport water along descending elevations of a ditch, continue to be popular because they provide low-cost irrigation systems.
During transportation of water through earthen ditches unlined by a material other than dirt, significant quantities of that ever more precious commodity, water, are lost because of seepage, erosion, trans-evaporation and other causes. Tests indicate that as much as 80–90% of water may be lost during transportation through an unlined earthen ditch before water is delivered to a point or area for application and use.
Accordingly, a number of approaches, suggestions and means for lining earthen ditches have been proposed or suggested. At least one prior approach for lining earthen ditches includes concrete. Concrete, however, is expensive to install, is substantially permanent, and requires erection of forms into which concrete must be formed to create necessary shapes. Other proposals for lining ditches have included use of various forms of metal, most often alloys of steel. Metal liners, however, have proven too rigid, too heavy to install easily, and unacceptable for a variety of environmental reasons. Polyvinyl chloride (“PVC”) also has been used, but in many locales liners made of PVC must be buried beneath ground because of environmental concerns.
Additional limitations of those prior approaches to transporting water through earthen ditches are significant. Not only are large quantities of water lost through seepage, erosion and evaporation, but unlined earthen ditches must constantly be maintained, cleaned and repaired to avoid further loss of water through wall collapse, accumulated debris, absorption through dirt walls, and capillary action. Repair and maintenance of ditches is costly and labor intensive. Limitations of prior approaches that involved lining earthen ditches with a variety of materials such as concrete, metal and more recently one or more forms of polyvinyl chloride materials, are expensive and unresponsive to modern environmental concerns. Such materials have proven difficult to install in remote geographical areas, inflexibly positioned once installed, and often require major construction efforts often neither practical nor affordable. Such materials also do not allow making component ditch parts that snap together to form a detachable but locked joint. Inability to readily direct and redirect water flow to other ditches or in other directions using concrete or steel also is a significant limitation on their use.
An exemplary solution to problems associated with lining earthen ditches was provided by one of the present inventors in U.S. Pat. No. 6,273,640 B1, issued to Kenneth L. Suazo on Aug. 14, 2001 (“Suazo Patent”). The Suazo Patent provided an irrigation ditch liner system comprising a plurality of liner sections that are sem-cylindrical in shape and employ a sem-cylindrical connector piece to connect liner sections along the course of a ditch.
To appreciate the additional advantages of the present invention, it is important first to appreciate the significant distances that an interconnected system of liner sections may traverse in a field environment during use and operation of the present invention. Ditch lengths exceeding five thousand feet are not uncommon. In many field environments, the rate at which water flows through a ditch also is significant. Frequently, a ditch master, or similar official, notifies a property owner when water for irrigation has been released upstream. It thereafter becomes the responsibility of the ditch owner to secure the allotment of water before it passes downstream.
It also should be appreciated that loss of water, commonly referred to as “seepage loss,” may be considerable. At least one report issued by New Mexico State University entitled “Field/laboratory Studies for the FastDitch Lining System,” dated Feb. 10, 2002 (“Report”), indicates the results of tests conducted over a nine day interval. Total water losses during the nine day test period were estimated to be 14,245,010 gallons, or 85.8% of total flow, when water was conducted through an unlined earthen ditch. The report attributes most water losses to existing vegetation overgrowth, tree root systems, gopher holes, evaporation, and seepage or percolation. On the other hand, that same report, based on field measurements taken with the liner system disclosed in the Suazo Patent installed in the same earthen ditch, showed a total loss of only 7.3% of total flow.
The present invention seeks to eliminate even that small amount of seepage loss. Further optimizations in connection with the Suazo Patent may be achieved as provided in connection with the present invention by providing alternative features and elements desirable for increasing the range and variety of differing applications and environments in which the present invention may be used. As indicated, a previously unaddressed need exists for a new, useful and improved apparatus and method for lining ditches that is easy to install, lightweight, will transport water efficiently at larger than customary flow rates while also reducing loss of water during conveyance, and will reduce maintenance problems that accompany insiltation, cleaning and maintenance of conventional earthen ditches and ditch liners.